EP0151169B1 - Axial-flow fan - Google Patents
Axial-flow fan Download PDFInfo
- Publication number
- EP0151169B1 EP0151169B1 EP84902914A EP84902914A EP0151169B1 EP 0151169 B1 EP0151169 B1 EP 0151169B1 EP 84902914 A EP84902914 A EP 84902914A EP 84902914 A EP84902914 A EP 84902914A EP 0151169 B1 EP0151169 B1 EP 0151169B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- fan
- rotor
- annular chamber
- upstream
- edge
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
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Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/40—Casings; Connections of working fluid
- F04D29/52—Casings; Connections of working fluid for axial pumps
- F04D29/522—Casings; Connections of working fluid for axial pumps especially adapted for elastic fluid pumps
- F04D29/526—Details of the casing section radially opposing blade tips
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/40—Casings; Connections of working fluid
- F04D29/52—Casings; Connections of working fluid for axial pumps
- F04D29/54—Fluid-guiding means, e.g. diffusers
- F04D29/541—Specially adapted for elastic fluid pumps
- F04D29/545—Ducts
- F04D29/547—Ducts having a special shape in order to influence fluid flow
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/66—Combating cavitation, whirls, noise, vibration or the like; Balancing
- F04D29/68—Combating cavitation, whirls, noise, vibration or the like; Balancing by influencing boundary layers
- F04D29/681—Combating cavitation, whirls, noise, vibration or the like; Balancing by influencing boundary layers especially adapted for elastic fluid pumps
- F04D29/685—Inducing localised fluid recirculation in the stator-rotor interface
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S415/00—Rotary kinetic fluid motors or pumps
- Y10S415/914—Device to control boundary layer
Definitions
- This invention relates to an axial-flow fan comprising a rotor and a surrounding casing.
- the rotor includes a hub and a plurality of rotor blades extending radially outwards from the hub, and the casing comprises an inlet section located in its entirety upstream of the rotor blades, an outlet section of substantially the same diameter as the inlet section and arranged with its upstream end located in a plane intermediate the leading and trailing edges of the rotor blades, and an intermediate section of larger diameter than the inlet and outlet sections to which it is connected airtight at the downstream and upstream ends, respectively, of those sections whereby the intermediate section defines an annular chamber partly overlapping the tips of the rotor blades.
- a plurality of stationary guide vanes are secured to the walls of the annular chamber and extend from the upstream to the downstream end thereof, whereby they divide the chamber into a plurality of compartments distributed along its circumference.
- the annular chamber which partly overlaps the rotor blade tips, is provided for obviating or at least mitigating some undesirable phenomena occurring when the rotor operates in the so- called stalling region or regime, i.e. at a low delivery rate and corresponding high angles of attack at the leading edges of the rotor blades.
- each stall vortex has, in addition to its proper swirl, a tangential and a radial velocity component.
- the tangential velocity component can be regarded as constant at a constant rate of revolution of the rotor, while the radial velocity component resulting from the centrifugal force increases with decreasing radius from the rotor axis to the point of the blade surface where flow separation starts. It has however been found that the angle included between the composite velocity vector and the radius from the blade tip varies relatively little with varying radius to the point of separation. When the inclination of the inlet zone of each vane is chosen within the defined range, it is possible to ensure that with reasonable approximation the direction of said inlet zone coincides with the velocity vector of the stall vortex, irrespective of the delivery rate of the fan.
- the cross-sectional profile of the guide vane i.e. a section therethrough perpendicular to the rotor axis, may be curvilinear with its concavity facing the direction of rotation of the rotor, with the guide vane meeting the outer or peripheral wall of the annular chamber at an angle of 90° ⁇ 10°.
- the flow reversal of the stall vortex at the bottom of the annular chamber takes place with minimal losses, possibly because secondary vortices, which would be created with a flat vane meeting the chamber bottom wall at an acute angle, are avoided.
- the upstream end portion of the radially inner edge of each guide vane may be radially retracted relative to the downstream end portion of that edge.
- the retracted end portion may expediently include from 25% to 35% of the total axial length of the vane edge.
- the inner edges of the guide vanes are interconnected by a ring having an inner diameter substantially equal to the diameters of the outlet and inlet sections of the casing and located axially between those sections so as to define inlet and outlet passages, respectively, to and from the annular chamber; the axial dimensions of said inlet and outlet passages are substantially equal and each of them is between 25% and 35% of the axial length of the annular chamber; and the retracted upstream end portions of the inner guide vane edges extend outwardly from the upstream end face of the interconnecting ring.
- this embodiment combines a substantial reduction of the disturbing influence, which the annular chamber unavoidably exerts on the normal operation of the fan, with practically unchanged favourable influence on the operation of the fan within the stalling regime, including improved stability and less vibrations and noise.
- the interconnecting ring which has been previously proposed in combination with guide vanes located in the outlet passage only of the annular chamber, i.e.
- the upstream part of that chamber, but not in the inlet passage improves the efficiency during normal operation (no reverse flow through the annular chamber) by reducing the flow resistance due to the presence of that chamber, the retracted or cut-off edges of the guide vanes defining the outlet passages from the individual compartments have been found to result in an unexpected further improvement of the optimum efficiency obtainable with a given fan.
- the retracted end portions of the vane edges follow straight lines or concave curves.
- the fan rotor has been illustrated by way of its hub 1 and a single blade 2 only, but it will be understood that there may be provided any suitable number of rotor blades, fixed or adjustable, and that the rotor hub is secured to a drive shaft (not shown) supported for rotation about an axis 3 in the direction of arrow 4 (Fig. 2).
- the outer fan casing generally designated by 5, comprises an inlet section 6, an intermediate section 7, and an outlet section 8.
- annular chamber generally designated by 9 is defined by the inner surfaces of the peripheral and end walls of section 7.
- Said end walls 10 and 11 are preferably flat, annular walls, as shown, and preferably the comer, where the downstream end wall 11 meets outlet section 8, is radiused as most clearly seen in Fig. 3.
- the upstream end wall 10 of chamber 9 is located upstream of the leading edges 12 of rotor blades 2 while the downstream end wall 11 is disposed axially between the leading edges and the trailing blade edges 13. Consequently there is a certain axial overlap between chamber 9 and the rotor blade tips and the magnitude of that overlap may expediently amount to approximately 30% of the length of the blade tips projected onto a plane through the rotor axis (as in Fig. 1). In a fan with angularly adjustable rotor blades the length referred to will be measured at an adjusted blade angle corresponding to maximum fan efficiency.
- each guide vane 14 is formed as part of a cylinder with constant or substantially constant radius of curvature and it is secured to the walls of section 7 in such a way that at the bottom of chamber 9 it adjoins the peripheral wall 15 thereof at an angle a which is approximately a right angle.
- Each guide vane 14 is arranged with its generatrices extending in parallel to axis 3 and with its concave surface oriented towards the direction of rotation of rotor 1, 2, as illustrated by arrow 4 in Fig. 2.
- each vane 14 forms an acute angle with a radius 17 connecting the inner edge of the vane with axis 3 (Fig. 4).
- the value of angle will be between 40° and 65°.
- each guide vane is composed of a downstream portion 18 which extends in parallel to axis 3, and an upstream portion 19 which, as illustrated, may be retracted so that it connects to end wall 10 at a point 20 which is offset radially outwards with respect to the point of junction 21 between edge portions 18 and 19.
- FIG. 5 shows the interrelation between the delivery rate Q and the fan pressure Py at different blade angles ranging from 25° to 55°, that throughout that range the pressure increases continually with decreasing delivery rate, and further that the fan may operate without noticeable stalling practically down to zero delivery.
- a broken line S in Fig. 5 indicates the approximate limit of the stall-free region of a similar fan without the annular chamber and the related features of the invention, as described above.
- Fig. 5 also includes a few curves representing operational conditions of constant efficiency. Bearing in mind that the fan will normally be designed to operate close to the point of maximum efficiency, it will be understood that the characteristics shown in Fig. 5 leave room for quite substantial temporary overloads.
- the guide vanes within the annular chamber may be oriented at an angle, which may range from 0° to 45°, with that axis.
- An effect of such skewed mounting of the vanes would be to further reduce the counterrotation, referred to above, of the air leaving chamber g through outlet passage 24, and thereby to arrive at discharge pressures at extremely low delivery rates which are somewhat lower than those shown in Fig. 5.
Abstract
Description
- This invention relates to an axial-flow fan comprising a rotor and a surrounding casing. The rotor includes a hub and a plurality of rotor blades extending radially outwards from the hub, and the casing comprises an inlet section located in its entirety upstream of the rotor blades, an outlet section of substantially the same diameter as the inlet section and arranged with its upstream end located in a plane intermediate the leading and trailing edges of the rotor blades, and an intermediate section of larger diameter than the inlet and outlet sections to which it is connected airtight at the downstream and upstream ends, respectively, of those sections whereby the intermediate section defines an annular chamber partly overlapping the tips of the rotor blades. A plurality of stationary guide vanes are secured to the walls of the annular chamber and extend from the upstream to the downstream end thereof, whereby they divide the chamber into a plurality of compartments distributed along its circumference.
- In an axial-flow fan of this type, which is known from the published specification of International Application No. PCT/AU81/00181 (W082/01919), the annular chamber, which partly overlaps the rotor blade tips, is provided for obviating or at least mitigating some undesirable phenomena occurring when the rotor operates in the so- called stalling region or regime, i.e. at a low delivery rate and corresponding high angles of attack at the leading edges of the rotor blades. When stalling occurs at a rotor blade the air flow becomes separated or detached from the convex side of the blade profile, and the resulting stall vortices will move outwardly, due to centrifugal forces, into the annular chamber and be directed back therefrom into the flow upstream of the rotor and mixed therewith. As a consequence of this recycling or backflow the axial inflow velocity at the leading blade edge increases and the angle of attack decreases correspondingly. The quoted specification discloses a plurality of fixed guide vanes disposed within the annular chamber and oriented radially relative to the rotor axis with their radial dimension decreasing to zero at the downstream end wall of the annular chamber. It has been explained in the specification that at low delivery rates there will be obtained a somewhat higher delivery pressure with the stationary guide vanes than without them.
- According to the present invention an axial -flow fan of the type defined in the opening paragraph above is characterized in that the radially innermost edge zone of each stationary guide vane is oriented towards the direction of rotation of the rotor and includes an angle of between 65° and 40° with a radius from the rotor axis to the inner edge of the vane.
- It has been found that by inclining the innermost edge zone of each vane, as provided by the invention, it is possible, inter alia, to eliminate the pressure drop which according to the above discussed prior specification occurs at very low delivery rates, even with guide vanes in the annular chamber. The pressure-versus- volume curves of the fan then exhibit a pressure maximum at or adjacent zero delivery, similar to the characteristics of a centrifugal fan. If the operational conditions of the fan include a risk of substantial overload due to temporarily increased flow resistance, the fan may then still operate at a correspondingly reduced delivery rate without stalling and at a reasonable efficiency.
- The advantages obtained by inclining the inner edge zones of the guide vanes are believed to be due to the fact that as soon as an outwardly traveling stall vortex loses contact with the tip of a rotor blade, the mass of air within the vortex is so to speak intercepted by an edge zone of a guide vane and guided, by the vane, into one of the compartments, into which the annular chamber is subdivided by the vanes. At the blade tip each stall vortex has, in addition to its proper swirl, a tangential and a radial velocity component. The tangential velocity component can be regarded as constant at a constant rate of revolution of the rotor, while the radial velocity component resulting from the centrifugal force increases with decreasing radius from the rotor axis to the point of the blade surface where flow separation starts. It has however been found that the angle included between the composite velocity vector and the radius from the blade tip varies relatively little with varying radius to the point of separation. When the inclination of the inlet zone of each vane is chosen within the defined range, it is possible to ensure that with reasonable approximation the direction of said inlet zone coincides with the velocity vector of the stall vortex, irrespective of the delivery rate of the fan.
- Excellent results have been obtained with guide vanes in which the angle included between said inner edge zone and the associated radius was 55° + 5°.
- The cross-sectional profile of the guide vane, i.e. a section therethrough perpendicular to the rotor axis, may be curvilinear with its concavity facing the direction of rotation of the rotor, with the guide vane meeting the outer or peripheral wall of the annular chamber at an angle of 90° ± 10°. In that embodiment the flow reversal of the stall vortex at the bottom of the annular chamber takes place with minimal losses, possibly because secondary vortices, which would be created with a flat vane meeting the chamber bottom wall at an acute angle, are avoided.
- According to a feature of the invention the upstream end portion of the radially inner edge of each guide vane may be radially retracted relative to the downstream end portion of that edge. The retracted end portion may expediently include from 25% to 35% of the total axial length of the vane edge.
- In a preferred embodiment of the invention, the inner edges of the guide vanes are interconnected by a ring having an inner diameter substantially equal to the diameters of the outlet and inlet sections of the casing and located axially between those sections so as to define inlet and outlet passages, respectively, to and from the annular chamber; the axial dimensions of said inlet and outlet passages are substantially equal and each of them is between 25% and 35% of the axial length of the annular chamber; and the retracted upstream end portions of the inner guide vane edges extend outwardly from the upstream end face of the interconnecting ring.
- It has been found that this embodiment combines a substantial reduction of the disturbing influence, which the annular chamber unavoidably exerts on the normal operation of the fan, with practically unchanged favourable influence on the operation of the fan within the stalling regime, including improved stability and less vibrations and noise. While the interconnecting ring, which has been previously proposed in combination with guide vanes located in the outlet passage only of the annular chamber, i.e. the upstream part of that chamber, but not in the inlet passage, improves the efficiency during normal operation (no reverse flow through the annular chamber) by reducing the flow resistance due to the presence of that chamber, the retracted or cut-off edges of the guide vanes defining the outlet passages from the individual compartments have been found to result in an unexpected further improvement of the optimum efficiency obtainable with a given fan.
- Preferably the retracted end portions of the vane edges follow straight lines or concave curves.
- The upstream end point of each retracted edge portion may be radially offset relative to the downstream end point thereof by an amount equal to between 20% and 100% of the radial depth of the annular chamber.
- The invention will be explained in more detail below with reference to the accompanying schematical drawings in which:
- Fig. 1 is an axial section through a preferred embodimentof an axial-flow fan embodying the present invention, whereby only one half of the rotor proper and the surrounding part of the fan casing have been shown,
- Fig. 2 is a fractional view taken along line 11-11 of Fig. 1,
- Fig. 3 is a section through the intermediate section of the fan casing only, similar to Fig. 1, but on a larger scale and corresponding to the sectional line III-III in Fig. 4,
- Fig. 4 is a section along line IV-IV of Fig. 3, and
- Fig. 5 is a diagram showing the relationship between the delivery rate and the pressure increase in a fan according to the invention and having adjustable blades.
- For the sake of clarity, only those component parts of the fan have been shown which are believed to be necessary for the understanding of the invention. Thus, in Figs. and 2 the fan rotor has been illustrated by way of its hub 1 and a
single blade 2 only, but it will be understood that there may be provided any suitable number of rotor blades, fixed or adjustable, and that the rotor hub is secured to a drive shaft (not shown) supported for rotation about anaxis 3 in the direction of arrow 4 (Fig. 2). The outer fan casing, generally designated by 5, comprises aninlet section 6, anintermediate section 7, and anoutlet section 8. Except for the funnel-shaped mouth ofinlet section 6, all three sections are cylindric with circular cross sections, and the inner diameters ofsections intermediate section 7 is larger so that an annular chamber generally designated by 9 is defined by the inner surfaces of the peripheral and end walls ofsection 7. Saidend walls downstream end wall 11 meetsoutlet section 8, is radiused as most clearly seen in Fig. 3. - The
upstream end wall 10 ofchamber 9 is located upstream of the leadingedges 12 ofrotor blades 2 while thedownstream end wall 11 is disposed axially between the leading edges and thetrailing blade edges 13. Consequently there is a certain axial overlap betweenchamber 9 and the rotor blade tips and the magnitude of that overlap may expediently amount to approximately 30% of the length of the blade tips projected onto a plane through the rotor axis (as in Fig. 1). In a fan with angularly adjustable rotor blades the length referred to will be measured at an adjusted blade angle corresponding to maximum fan efficiency. - Within the annular chamber 9 a plurality of
stationary guide vanes 14 have been secured, e.g. by welding, to theperipheral wall 15 ofsection 7 and toend walls guide vane 14 is formed as part of a cylinder with constant or substantially constant radius of curvature and it is secured to the walls ofsection 7 in such a way that at the bottom ofchamber 9 it adjoins theperipheral wall 15 thereof at an angle a which is approximately a right angle. Eachguide vane 14 is arranged with its generatrices extending in parallel toaxis 3 and with its concave surface oriented towards the direction of rotation ofrotor 1, 2, as illustrated by arrow 4 in Fig. 2. Accordingly, the radially innermost edge zone of eachvane 14, more particular thetangent 16 thereto, forms an acute angle with aradius 17 connecting the inner edge of the vane with axis 3 (Fig. 4). According to the invention the value of angle will be between 40° and 65°. - The inner edge of each guide vane is composed of a
downstream portion 18 which extends in parallel toaxis 3, and anupstream portion 19 which, as illustrated, may be retracted so that it connects toend wall 10 at apoint 20 which is offset radially outwards with respect to the point ofjunction 21 betweenedge portions - The
downstream edge portions 18 of allvanes 14 are interconnected by means of aring 22 which, as shown in Fig. 3, extends in the downstream direction frompoint 21. In addition to providing a mechanical connection betweenvanes 14, to which it may be welded,ring 22 serves to define, in connection with theend walls chamber 9 aninlet passage 23 to that chamber and anoutlet passage 24 therefrom, respectively. Preferably thering 22 is arranged such that the axial dimensions ofpassages walls ring 22 is the same as the inner diameter ofsections casing 5, and shown in Fig. 3 its upstream end, atpoint 21, should be radiused. like the edge where well 11 joinsoutlet section 8. - If stalling occurs at one or more of the
rotor blades 2 due to flow separation on the convex blade surface, there will be formed one or more swirling vortices which, due to the centrifugal force acting on the mass of air therein, travel outwardly along the blade surface until they enter theannular chamber 9 through theinlet passage 23 thereto. As mentioned above the swirling vortices also rotate aboutaxis 3, although with a tangential or angular velocity lower than the tangential or angular velocity ofrotor 1, 2. The last mentioned rotation of each vortex is decelerated when the vortex flows into one of the compartments orcells 25 which are defined withinchamber 9 betweensuccessive guide vanes 14. From the bottom of eachcompartment 25 the vortex is reflected radially inwards so as to leave thecompartment 25 throughoutlet passage 24. - The recycled air flowing out of a
compartment 25 throughpassage 24 to get mixed with the incoming air flowing in the direction of arrow 26 (Fig. 1) throughinlet section 6, will have a certain component of rotation counter to the direction in whichrotor 1, 2 rotates. This counterrotation, which is due to the particular shape and orientation ofguide vanes 14, will to some extent be reduced by the outward inclination ofvane edges 19, and the reduction will be larger, the larger the outward offset ofend point 20 is. This offset may go up to 100% in whichcase point 20 would coincide with the intersection ofchamber walls chamber 9, as measured betweenwall 15 andring 22. Preferably the latter dimension ofchamber 9 is approximately 40% of the inner distance betweenend walls - It will be seen from the diagram of Fig. 5, which shows the interrelation between the delivery rate Q and the fan pressure Py at different blade angles ranging from 25° to 55°, that throughout that range the pressure increases continually with decreasing delivery rate, and further that the fan may operate without noticeable stalling practically down to zero delivery. A broken line S in Fig. 5 indicates the approximate limit of the stall-free region of a similar fan without the annular chamber and the related features of the invention, as described above. Fig. 5 also includes a few curves representing operational conditions of constant efficiency. Bearing in mind that the fan will normally be designed to operate close to the point of maximum efficiency, it will be understood that the characteristics shown in Fig. 5 leave room for quite substantial temporary overloads.
- Finally, it may be mentioned that instead of being mounted in parallel to the rotor axis, the guide vanes within the annular chamber may be oriented at an angle, which may range from 0° to 45°, with that axis. An effect of such skewed mounting of the vanes would be to further reduce the counterrotation, referred to above, of the air leaving chamber g through
outlet passage 24, and thereby to arrive at discharge pressures at extremely low delivery rates which are somewhat lower than those shown in Fig. 5.
Claims (10)
a casing (5) surrounding the rotor and comprising an inlet section (6) located in its entirety upstream of the rotor blades, an outlet section (8) of substantially the same diameter as the inlet section and arranged with its upstream end located in a plane intermediate the leading and trailing edges (12,13) of the rotor blades, and an intermediate section (7) of larger diameter than the inlet and outlet sections and connected airtight to the downstream and upstream ends, respectively, of those sections thereby defining an annular chamber (9) parity overlapping the tips of the rotor blades,
and a plurality of guide vanes (14) secured to the walls (10, 11, 15) of the annular chamber and extending from the upstream to the downstream end thereof, thus dividing the chamber into a plurality of compartments (25) distributed along its circumference,
characterized in that the radially innermost edge zone of each guide vane (14) is oriented towards the direction of rotation (4) of the rotor and includes an angle of between 65° and 40° with a radius (17) connecting the inner edge (18) of the vane with the rotor axis (3).
that the axial dimensions of said inlet and outlet passages (23, 24) are substantially equal and each is between 25% and 35% of the axial length of the annular chamber (9),
and the retracted upstream end portions (19) of the inner guide vane edges extend outwardly from the upstream end face (21) of the interconnecting ring (22).
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AT84902914T ATE25540T1 (en) | 1983-07-28 | 1984-07-23 | AXIAL FAN. |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DK3458/83A DK345883D0 (en) | 1983-07-28 | 1983-07-28 | axial |
DK3458/83 | 1983-07-28 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0151169A1 EP0151169A1 (en) | 1985-08-14 |
EP0151169B1 true EP0151169B1 (en) | 1987-02-25 |
Family
ID=8123097
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP84902914A Expired EP0151169B1 (en) | 1983-07-28 | 1984-07-23 | Axial-flow fan |
Country Status (8)
Country | Link |
---|---|
US (1) | US4630993A (en) |
EP (1) | EP0151169B1 (en) |
JP (1) | JPS60501910A (en) |
AU (1) | AU572546B2 (en) |
DE (1) | DE3462413D1 (en) |
DK (1) | DK345883D0 (en) |
FI (1) | FI89975C (en) |
WO (1) | WO1985000640A1 (en) |
Families Citing this family (22)
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DE3539604C1 (en) * | 1985-11-08 | 1987-02-19 | Turbo Lufttechnik Gmbh | Axial fan |
GB2202585B (en) * | 1987-03-24 | 1991-09-04 | Holset Engineering Co | Improvements in and relating to compressors |
CH675279A5 (en) * | 1988-06-29 | 1990-09-14 | Asea Brown Boveri | |
JPH04132899A (en) * | 1990-09-25 | 1992-05-07 | Mitsubishi Heavy Ind Ltd | Axial blower |
KR100198721B1 (en) * | 1991-01-30 | 1999-06-15 | 레비스 스테픈 이 | Rotor case treatment |
US5282718A (en) * | 1991-01-30 | 1994-02-01 | United Technologies Corporation | Case treatment for compressor blades |
US5489186A (en) * | 1991-08-30 | 1996-02-06 | Airflow Research And Manufacturing Corp. | Housing with recirculation control for use with banded axial-flow fans |
US5277541A (en) * | 1991-12-23 | 1994-01-11 | Allied-Signal Inc. | Vaned shroud for centrifugal compressor |
ATE216757T1 (en) * | 1993-08-30 | 2002-05-15 | Bosch Robert Corp | HOUSING WITH RECIRCULATION CONTROL FOR USE IN AXIAL FANS WITH FRAME |
GB9400254D0 (en) * | 1994-01-07 | 1994-03-02 | Britisch Technology Group Limi | Improvements in or relating to housings for axial flow fans |
US5474417A (en) * | 1994-12-29 | 1995-12-12 | United Technologies Corporation | Cast casing treatment for compressor blades |
US5586859A (en) * | 1995-05-31 | 1996-12-24 | United Technologies Corporation | Flow aligned plenum endwall treatment for compressor blades |
AU6465398A (en) * | 1997-04-04 | 1998-10-30 | Bosch Automotive Systems Corporation | Centrifugal fan with flow control vanes |
US6302640B1 (en) | 1999-11-10 | 2001-10-16 | Alliedsignal Inc. | Axial fan skip-stall |
US7066365B2 (en) * | 2002-05-01 | 2006-06-27 | Brown Michael S | Transportable shooting apparatus |
US20030236489A1 (en) | 2002-06-21 | 2003-12-25 | Baxter International, Inc. | Method and apparatus for closed-loop flow control system |
GB0216952D0 (en) * | 2002-07-20 | 2002-08-28 | Rolls Royce Plc | Gas turbine engine casing and rotor blade arrangement |
US7478993B2 (en) * | 2006-03-27 | 2009-01-20 | Valeo, Inc. | Cooling fan using Coanda effect to reduce recirculation |
ATE444448T1 (en) * | 2006-05-31 | 2009-10-15 | Bosch Gmbh Robert | AXIAL FAN ARRANGEMENT |
CN101668678B (en) * | 2006-12-28 | 2012-02-08 | 开利公司 | Axial fan device and its manufacture method |
JP5479021B2 (en) * | 2009-10-16 | 2014-04-23 | 三菱重工業株式会社 | Exhaust turbocharger compressor |
DE102016119916A1 (en) * | 2016-10-19 | 2018-04-19 | Ebm-Papst Mulfingen Gmbh & Co. Kg | Fan with fan wheel and stator |
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NL45457C (en) * | ||||
US2327841A (en) * | 1940-06-12 | 1943-08-24 | B F Sturtevant Co | Propeller fan |
US2653754A (en) * | 1949-11-01 | 1953-09-29 | Westinghouse Electric Corp | Axial flow fan regulator |
US3677660A (en) * | 1969-04-08 | 1972-07-18 | Mitsubishi Heavy Ind Ltd | Propeller with kort nozzle |
AU540554B2 (en) * | 1980-12-03 | 1984-11-22 | James Howden Australia Pty. Ltd. | Stall-free axial flow fan |
US4511308A (en) * | 1980-12-03 | 1985-04-16 | James Howden Australia Pty. Limited | Axial and mixed flow fans and blowers |
JPS57110800A (en) * | 1980-12-26 | 1982-07-09 | Matsushita Seiko Co Ltd | Axial-flow type blower |
US4375937A (en) * | 1981-01-28 | 1983-03-08 | Ingersoll-Rand Company | Roto-dynamic pump with a backflow recirculator |
SE451873B (en) * | 1982-07-29 | 1987-11-02 | Do G Pk I Experiment | AXIALFLEKT |
SE451620B (en) * | 1983-03-18 | 1987-10-19 | Flaekt Ab | PROCEDURE FOR MANUFACTURING THE LINK CIRCLE FOR BACKGROUND CHANNEL BY AXIAL FLOWERS |
JPS6330519A (en) * | 1986-07-25 | 1988-02-09 | Yokohama Rubber Co Ltd:The | Thermosetting resin composition |
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1983
- 1983-07-28 DK DK3458/83A patent/DK345883D0/en not_active Application Discontinuation
-
1984
- 1984-07-23 WO PCT/DK1984/000070 patent/WO1985000640A1/en active IP Right Grant
- 1984-07-23 AU AU32176/84A patent/AU572546B2/en not_active Expired
- 1984-07-23 US US06/717,265 patent/US4630993A/en not_active Expired - Lifetime
- 1984-07-23 EP EP84902914A patent/EP0151169B1/en not_active Expired
- 1984-07-23 JP JP59503069A patent/JPS60501910A/en active Granted
- 1984-07-23 DE DE8484902914T patent/DE3462413D1/en not_active Expired
-
1985
- 1985-03-27 FI FI851236A patent/FI89975C/en not_active IP Right Cessation
Also Published As
Publication number | Publication date |
---|---|
AU3217684A (en) | 1985-03-04 |
DK345883D0 (en) | 1983-07-28 |
JPS60501910A (en) | 1985-11-07 |
JPH0512560B2 (en) | 1993-02-18 |
FI89975B (en) | 1993-08-31 |
WO1985000640A1 (en) | 1985-02-14 |
US4630993A (en) | 1986-12-23 |
EP0151169A1 (en) | 1985-08-14 |
FI851236A0 (en) | 1985-03-27 |
DE3462413D1 (en) | 1987-04-02 |
AU572546B2 (en) | 1988-05-12 |
FI89975C (en) | 1993-12-10 |
FI851236L (en) | 1985-03-27 |
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